There are alternative possible ways of providing the necessary mechanical engagement between the various component members of the fastener. The remote end of the pin may have a radially protruding head which contacts the end of the sleeve to apply compressive force to it, or the remote end of the pin may be in threaded engagement with the sleeve.
The abutment member is secured to the near end of the sleeve, to enable correct insertion of the fastener into the aperture through the workpiece.
One such fastener is that commercially available under the trade mark “HUCK BOM”, which is described in U.S. Pat. No. 2,527,307. In this fastener, the abutment is in the form of a radially enlarged head integral with the sleeve.
In use, it is sometimes found that it is necessary to remove a fastener which has been installed in a workpiece, e.g. for servicing or repairing the equipment of which the workpiece forms a part. It is extremely difficult to do this, since the abutment member is swaged on to the pin, and is integral with the sleeve. The pin is too hard to drill out. In any event, it is unacceptable for removal of the fastener to cause damage to the adjacent part of the workpiece.
The present invention is intended to provide a fastener of this type which can, if needed, be removed more easily and conveniently.